1. Field of the Invention
The present invention generally relates to an array substrate and a repairing method thereof, and more particularly, to an active device array substrate and a repairing method thereof.
2. Description of Related Art
In a flat panel display, pixels are arranged into an array and display images under the control of two sets of perpendicularly disposed signal lines. The design with scan lines and data lines is the most commonly adopted design among all image control modes. The scan lines and the data lines are perpendicular to each other so as to define a plurality of pixels. The scan lines are sequentially activated to turn on or turn off the corresponding switch devices, so that signals transmitted on the data lines can be written into the pixels and accordingly the display conditions of the corresponding pixels can be changed.
Even though the flat panel display technology has matured gradually, some defects may still be occurred on components (for example, an active device array substrate) of a flat panel display when the flat panel display is manufactured. For example, the scan lines and data lines on an active device array substrate are very long and open defects may be occurred. When open defects are occurred in a scan line or a data line, some pixels arranged in a same row or arranged in a same column malfunctions and line defect may occurred. Thus, any open defect should be repaired. In addition, it is very difficult to achieve a minimal defect rate by simply improving the manufacturing process. Thus, a repairing structure and a defect repairing technique in an active device array substrate have become necessary. Conventionally, defects in an active device array substrate are usually repaired through laser welding and/or laser cutting.
Generally speaking, at least one repairing line is usually preserved on an active device array substrate in order to repair any open defect instantly. Normally, the repairing line is intersected with the signal lines with welding points and is electrically insulated from the signal lines. When an open defect is occurred on a signal line and accordingly the signal line is broken, two ends of the signal line having open defect are respectively welded to the repairing line through welding points so that the signal line having open defect can remain connected through the repairing line and the corresponding pixels can function properly.
In other words, the repairing line is normally electrically floated and electrically insulated from the signal lines, and it is only electrically connected to a signal line (so as to keep the signal line active) through laser welding when the signal line is broken. However, it should be noted that the signal lines and the repairing line may be damaged by electrostatic discharge (ESD) and short circuited. As a result, the display quality of the active device array substrate may be affected, and even worse, the active device array substrate may be declared no longer serviceable.